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Fixed crash in GetClientInfo() native on L4D (bug 3569, r=me).

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The CreateFakeClient signature (used for verification before retrieving the IServer interface pointer) changed in a recent update. The IServer pointer was therefore null and GetClientInfo() did not check for this.

The CreateFakeClient signature is also no longer hardcoded. It is modifiable in gamedata/sdktools.games/engine.*.txt.
This commit is contained in:
Scott Ehlert 2009-01-22 15:20:45 -06:00
parent 80602b011d
commit 22675ba2e7
5 changed files with 113 additions and 26 deletions
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90
extensions/sdktools/vglobals.cpp
View File

@ -83,12 +83,49 @@ void InitializeValveGlobals()
}
#endif
bool vcmp(const void *_addr1, const void *_addr2, size_t len)
size_t UTIL_StringToSignature(const char *str, char buffer[], size_t maxlength)
{
unsigned char *addr1 = (unsigned char *)_addr1;
unsigned char *addr2 = (unsigned char *)_addr2;
size_t real_bytes = 0;
size_t length = strlen(str);
for (size_t i=0; i<len; i++)
for (size_t i=0; i<length; i++)
{
if (real_bytes >= maxlength)
{
break;
}
buffer[real_bytes++] = (unsigned char)str[i];
if (str[i] == '\\'
&& str[i+1] == 'x')
{
if (i + 3 >= length)
{
continue;
}
/* Get the hex part */
char s_byte[3];
int r_byte;
s_byte[0] = str[i+2];
s_byte[1] = str[i+3];
s_byte[2] = '\n';
/* Read it as an integer */
sscanf(s_byte, "%x", &r_byte);
/* Save the value */
buffer[real_bytes-1] = (unsigned char)r_byte;
/* Adjust index */
i += 3;
}
}
return real_bytes;
}
bool UTIL_VerifySignature(const void *addr, const char *sig, size_t len)
{
unsigned char *addr1 = (unsigned char *) addr;
unsigned char *addr2 = (unsigned char *) sig;
for (size_t i = 0; i < len; i++)
{
if (addr2[i] == '*')
continue;
@ -100,34 +137,20 @@ bool vcmp(const void *_addr1, const void *_addr2, size_t len)
}
#if defined PLATFORM_WINDOWS
/* Thanks to DS for the sigs */
#define ISERVER_WIN_SIG "\x8B\x44\x24\x2A\x50\xB9\x2A\x2A\x2A\x2A\xE8"
#define ISERVER_WIN_SIG_LEN 11
void GetIServer()
{
const char *sigstr;
char sig[32];
size_t siglen;
int offset;
void *vfunc = NULL;
/* Get the offset into CreateFakeClient */
if (!g_pGameConf->GetOffset("sv", &offset))
{
return;
}
#if defined METAMOD_PLAPI_VERSION
/* Get the CreateFakeClient function pointer */
if (!(vfunc=SH_GET_ORIG_VFNPTR_ENTRY(engine, &IVEngineServer::CreateFakeClient)))
{
return;
}
/* Check if we're on the expected function */
if (!vcmp(vfunc, ISERVER_WIN_SIG, ISERVER_WIN_SIG_LEN))
{
return;
}
/* Finally we have the interface we were looking for */
iserver = *reinterpret_cast<IServer **>(reinterpret_cast<unsigned char *>(vfunc) + offset);
#else
/* Get the interface manually */
SourceHook::MemFuncInfo info = {true, -1, 0, 0};
@ -139,14 +162,33 @@ void GetIServer()
void **vtable = *reinterpret_cast<void ***>(enginePatch->GetThisPtr() + info.thisptroffs + info.vtbloffs);
vfunc = vtable[info.vtblindex];
}
/* Check if we're on the expected function */
if (!vcmp(vfunc, ISERVER_WIN_SIG, ISERVER_WIN_SIG_LEN))
#endif
/* Get signature string for IVEngineServer::CreateFakeClient() */
sigstr = g_pGameConf->GetKeyValue("CreateFakeClient_Windows");
if (!sigstr)
{
return;
}
/* Convert signature string to signature bytes */
siglen = UTIL_StringToSignature(sigstr, sig, sizeof(sig));
/* Check if we're on the expected function */
if (!UTIL_VerifySignature(vfunc, sig, siglen))
{
return;
}
/* Get the offset into CreateFakeClient */
if (!g_pGameConf->GetOffset("sv", &offset))
{
return;
}
/* Finally we have the interface we were looking for */
iserver = *reinterpret_cast<IServer **>(reinterpret_cast<unsigned char *>(vfunc) + offset);
#endif
}
#elif defined PLATFORM_POSIX
void GetIServer()

8
extensions/sdktools/vnatives.cpp
View File

@ -962,8 +962,14 @@ static cell_t ActivateEntity(IPluginContext *pContext, const cell_t *params)
static cell_t SetClientInfo(IPluginContext *pContext, const cell_t *params)
{
if (iserver == NULL)
{
return pContext->ThrowNativeError("IServer interface not supported, file a bug report.");
}
IGamePlayer *player = playerhelpers->GetGamePlayer(params[1]);
IClient *pClient = iserver->GetClient(params[1]-1);
IClient *pClient = iserver->GetClient(params[1] - 1);
if (player == NULL || pClient == NULL)
{
return pContext->ThrowNativeError("Invalid client index %d", params[1]);

13
gamedata/sdktools.games/engine.ep1.txt
View File

@ -196,6 +196,19 @@
/* IServer interface pointer */
"#default"
{
"Keys"
{
/* Signature for the beginning of IVEngineServer::CreateFakeClient.
*
* The engine binary is not actually scanned in order to look for
* this. SourceHook is used to used to determine the address of the
* function and this signature is used to verify that it contains
* the expected code. A pointer to sv (IServer interface) is used
* here.
*/
"CreateFakeClient_Windows" "\x8B\x44\x24\x2A\x50\xB9\x2A\x2A\x2A\x2A\xE8"
}
"Offsets"
{
/* Offset into IVEngineServer::CreateFakeClient */

13
gamedata/sdktools.games/engine.ep2.txt
View File

@ -167,6 +167,19 @@
/* IServer interface pointer */
"#default"
{
"Keys"
{
/* Signature for the beginning of IVEngineServer::CreateFakeClient.
*
* The engine binary is not actually scanned in order to look for
* this. SourceHook is used to used to determine the address of the
* function and this signature is used to verify that it contains
* the expected code. A pointer to sv (IServer interface) is used
* here.
*/
"CreateFakeClient_Windows" "\x8B\x44\x24\x2A\x50\xB9\x2A\x2A\x2A\x2A\xE8"
}
"Offsets"
{
/* Offset into IVEngineServer::CreateFakeClient */

15
gamedata/sdktools.games/engine.l4d.txt
View File

@ -166,12 +166,25 @@
/* IServer interface pointer */
"#default"
{
"Keys"
{
/* Signature for the beginning of IVEngineServer::CreateFakeClient.
*
* The engine binary is not actually scanned in order to look for
* this. SourceHook is used to used to determine the address of the
* function and this signature is used to verify that it contains
* the expected code. A pointer to sv (IServer interface) is used
* here.
*/
"CreateFakeClient_Windows" "\x55\x8B\xEC\x83\xEC\x08\x89\x4D\xF8\x8B\x45\x08\x50\xB9\x2A\x2A\x2A\x2A\xE8"
}
"Offsets"
{
/* Offset into IVEngineServer::CreateFakeClient */
"sv"
{
"windows" "6"
"windows" "14"
}
}